Field of the Invention
The present invention relates to a method and apparatus for detecting the presence of subterranean accumulations of hydrocarbons and is more particularly concerned with a method and apparatus used to carry out the method of analysis of cuttings or cores from drill holes for the purpose of determining the proximity of oil or gas producing formations.
It is commonly known in the geochemical field that the adsorptive power of various soil samples will affect the amounts of entrained gas or oil. It is also known in the field that the relative amount of hydrocarbons present in samples of cores collected in drilling oil and gas wells is an indication of the proximity of accumulations of hydrocarbons to the points from which the samples of earth were obtained.
Because certain rock formations can hold and adsorb hydrocarbons better than others, it is a general practice to analyze the core samples for their mineral contents. Several other important measurements are made on the samples, such as the determination of the permeability, porosity and density of core samples taken from various depths. These measurements yield significant information for the geologist. For example, the porosity of the formation is related to the amount of gas or oil contained in the formation. The measurement of permeability is an indication of the producability of the trapped gas or oil.
The permeability, porosity and density of the core samples, coupled with the water and hydrocarbon content of the samples and an analysis of their mineral content will determine the fluids expected to be produced from the oil well, the possible rate of production and the total amount which will ultimately be produced.